function showAlert() {
  var alert = document.getElementById('alert');
  alert.style.display = 'flex';
}

function hideAlert() {
  var alert = document.getElementById('alert');
  alert.style.display = 'none';

  // 添加跳转链接
  window.location.href = 'http://127.0.0.1:8000/userlogin/';
}